ObjectDB Database Search

The ORDER BY clause specifies a required order for the query results. Any JPQL query that does not include an ORDER BY clause produces results in an undefined and non-deterministic order . ORDER BY ... is at least one million people, ordered by the country name: SELECT c.name FROM Country c WHERE c.population 1000000

when ordering the results of some projection when the order by expression is different (though logically ... ;  + " order by s_location.id asc";         ... ;  + " order by s.location.id asc";        

performance I noticed a strange behaviour where an ORDER BY - directive isn't executed as it should be (and usually is, except in this special combination-case). Ordering seems to be ignored if we order by a simple member (e.g. a String) being the Entity-ID and, at the same time, filter

JPA Interface Order An object that defines an ordering over the query results. Since: JPA 2.0 The ORDER BY clause (JPQL / Criteria API) article explains how to use Order . Public Methods Expression getExpression () Return the expression that is used for ordering . Return: expression used

JPA Method in jakarta.persistence.criteria. Order Order reverse () Switch the ordering . Return: a new {@code Order } instance with the reversed ordering Since: JPA 2.0

JPA Method in jakarta.persistence.criteria. Order Expression getExpression () Return the expression that is used for ordering . Return: expression used for ordering Since: JPA 2.0

JPA Method in jakarta.persistence.criteria. Order boolean isAscending () Whether ascending ordering is in effect. Return: boolean indicating whether ordering is ascending Since: JPA 2.0

JPA Method in jakarta.persistence.criteria. Order Nulls getNullPrecedence () Return the precedence of null values. Return: the {@linkplain Nulls precedence of null values} Since: JPA 3.2

The JPA Criteria API interfaces in this group are used for setting the SELECT and ORDER BY clauses ... of Selection : See the SELECT in Criteria Queries section for more details and examples. ORDER BY Clause Elements Elements in the ORDER BY clause are represented by the Order interface: The Order

The members attribute is also required in order to define indexes on multi part paths: @Entity @Index ... for every index. A BTree is an ordered map data structure that ObjectDB maintains in the file ... because the index uses the lexicographic order of the words and is not ordered by the length of the words

;or the Window Open Table Window  commands in order to specify a preferred viewer window type ... command. The order of elements in an ordered collection can be modified by using the Edit Move Element ... and their order of appearance. This may be useful when working with classes with a large number of fields

Order If more than one callback method has to be invoked for a lifecycle event (e.g. from multiple listeners) the invocation order is based on the following rules: All the external callback methods ... . If there is more than one default listener or more than one listener at the same level in the hierarchy, the invocation order

...]] [ ORDER BY ...] The first two clauses, SELECT and FROM are required in every retrieval query ... , HAVING and ORDER BY are optional. The structure of JPQL DELETE and UPDATE queries is simpler: DELETE ... , ...). Criteria ORDER BY  ( orderBy , Order , asc , desc ).

Primary Keys for Object Clustering Entity objects are physically stored in the database ordered by ... ; } Because entity objects are ordered in the database by their primary key, events of the same sensor ... and a benchmark might be needed to evaluate the different alternatives in order to select the best solution.

it might be necessary to record "all" operations in order to reproduce the problem. Naturally, the recording operation ... the background, a soon as new indexes are detected, in order to activate these new indexes. The 

Map . For an inverse list field, the order of the retrieved owner entities can be set by the OrderBy ... of the following query: SELECT e FROM Employee e WHERE e.department = :d ORDER BY e.name The specified field

these details to connect to the master server in order to listen to updates. The updates ... =a"); A slightly different URL is required in order to access the slave database: EntityManagerFactory emf

Query expressions are the foundations on which JPQL and criteria queries are built. Every query consists of clauses - SELECT, FROM, WHERE, GROUP BY, HAVING and ORDER BY, and each clause consists ... the following operators (in order of decreasing precedence): Navigation operator (.) Arithmetic operators

In JPA a database connection is represented by the EntityManager interface. Therefore, in order to manipulate an ObjectDB database we need an EntityManager instance. Operations that modify database ... to get an EntityManager instance. JPA requires the definition of a persistence unit in an XML file in order

string. A query can be run only after setting values for all its parameters (no matter in which order ... values require special methods in order to specify what they represent, such as a pure date, a pure time

A prior knowledge of database programming (SQL, JDBC, ORM or JPA) is not required in order to follow ... . Further Reading and Resources This guide focuses mainly on practical issues in order to make the reader

intellectual property infringement. In order to qualify, an Indemnified Contributor must: a) promptly notify ... . Everyone is permitted to copy and distribute copies of this Agreement, but in order to avoid inconsistency

are also used for fast ordering and aggregate calculations . Lazy/Eager Loading Automatic pre-loading ... and aggregates ). ORDER BY (including ASC, DESC). Aggregates (COUNT, SUM, AVG, MAX, MIN). Query

( where ). GROUP BY / HAVING clauses ( groupBy , having , count , sum , avg , min , max , ...). ORDER BY clause ( orderBy , Order , asc , desc ). The links above are direct links to the criteria query

is executed, uncommitted database changes (if any) have to be flushed to the database in order

order to support optional arguments and when applicable simple Java objects as well as criteria expressions.

, MOD, NEW, NOT, NULL, NULLIF, OBJECT, OF, OR, ORDER , OUTER, POSITION, SELECT, SET, SIZE, SOME, SQRT

of these documentation pages is to serve as a reference. In order to learn how to use JPA and ObjectDB please read the ObjectDB manual .

are organized in this reference into three groups. SELECT and ORDER BY elements (including tuples): FROM clause

accessing ObjectDB cannot be enhanced, so a careful organization of the code is essential in order

order to interact with a relational database such as Oracle, DB2, SQL Server or MySQL. The popular JPA

, and cannot include the GROUP BY, HAVING and ORDER BY clauses. A WHERE clause, which is essential

that ability and require multiple tables, multiple records and join operations in order to support

running ObjectDB Doctor's diagnosis regularly in order to identify potential problems early

Existing entity objects can be deleted from the database either explicitly by invoking the remove method or implicitly as a result of a cascade operation. Explicit Remove In order to delete an object from the database it has to first be retrieved (no matter which way) and then in an active

provides two properties that can be used in order to change the default behavior. javax.persistence

UPDATE queries cannot include the GROUP BY, HAVING and ORDER BY clauses, but the WHERE clause

, and they can be used in ordering . Navigation through Path Expressions A path expression always starts

The GROUP BY clause enables grouping of query results. A JPQL query with a GROUP BY clause returns properties of generated groups instead of individual objects and fields. The position of a GROUP BY clause in the query execution order is after the FROM and WHERE clauses, but before the SELECT

can also be set for a query in order to lock all the query result objects. When a retrieval operation includes

BY, HAVING, ORDER BY): Then the expressions that are used for building JPQL and criteria query

the path to the file, and password , which specifies a password that is needed in order to use the file

This tutorial demonstrates how to create reports based on data in an ObjectDB database using the popular open source Business Intelligence and Reporting Tools (BIRT). In order to keep things as simple as possible - we will use the basic  points.odb ObjectDB database file from the Getting

Tutorial Only basic Java experience is required in order to follow this tutorial. Web Application

getAllGuests() { TypedQuery query = em.createQuery( "SELECT g FROM Guest g ORDER BY g.id", Guest.class

() { TypedQuery query = em.createQuery( "SELECT g FROM Guest g ORDER BY g.id", Guest.class); return

In this step we will add code to the Main class (that was generated with the project) in order to store Point objects in the database and then retrieve them from the database. Use copy and paste to replace the content of the Main class with the following content: package tutorial; import javax

getAllGuests() { TypedQuery query = em.createQuery( "SELECT g FROM Guest g ORDER BY g.id", Guest.class); return

Guest g ORDER BY g.id", Guest.class); return query.getResultList(); } } The GuestDao session bean (EJB

The following interfaces can be implemented by persistence capable classes in order to response to JDO lifecycle events: